A New Bitvectors Library For PVS

This paper describes a bitvectors library that has been developed for PVS. The library de nes a bitvector as a function from a subrange of the integers into booleans. The library provides functions that interpret a bitvector as a natural number, as a 2's complement number, as a vector of logical values and as a 2's complement fraction. The library provides a concatenation operator and an extractor. Shift, extend and rotate operations are also de ned. Fundamental properties of each of these operations have been proved in PVS. This library is an improvement over the earlier bitvectors library documented in NASA Technical Memorandum 110274 \A Bitvectors Library For PVS", August 1996.